The use of size enlargement techniques to build up solid masses from small particulate materials such as catalysts, metal powders, fertilizers and various other small particulate materials is well-known. Such size enlargement techniques have included sintering, extrusion, briquetting, pelleting, nodulizing and granulating, to name but a few. While there exist numerous reasons for employing size enlargement techniques to build up solid masses from small particulate materials, some of the more significant reasons are to densify such materials for more convenient storage and shipment, to reduce dust nuisance, to prevent caking and lumping of the materials, to reduce dust losses during handling, and the like.
Although the advantages of size enlargement are numerous, the use of size enlargement to obtain these advantages is not without drawbacks. For example, it generally is agreed that in order to maintain or even enhance the rate of dissolution of certain materials such as water soluble, solid inorganic compounds, e.g., particulate borates and inorganic salts of the alkali metals, it is highly desirable that these solid inorganic compounds be relatively finely divided. Thus, when such compounds are subjected to size enlargement to increase their density or to reduce their tendency to dust, it has been found that the rate of dissolution of these compounds is significantly decreased.
The present invention provides for solid articles of manufacture prepared from finely divided powers of spray dried, water soluble compounds, but which solid articles retain the ready solubility of powdery compounds from which they are prepared.